Air pump



FIG. 1 is a perspective view of an air pump showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a rear view thereof, and,

FIG. 6 is a bottom view thereof. 

The ornamental design for an air pump, as shown. 